Comments on New DNA & Stool-Based Screening Tests to FDA

This week Fight Colorectal Cancer is providing comments to the FDA as they consider two new screening technologies for colorectal cancer. Below are our opinions and recommendations presented to the Molecular and Clinical Genetics Panel as part of the Medical Devices Advisory Committee.


This week, the Food & Drug Administration (FDA) is hosting an advisory committee meeting with many stakeholders that have an interest in two new potential screening technologies, Epi proColon (by Epigenomics) and Cologuard (by Exact Sciences). Kim Ryan, our Director of Patient Information Services and advocate Marcia Mullins are attending to provide comments as the FDA considers these two new screening technologies.  

About Epi proColon & Cologuard

Epi proColon is a blood-based screening test that looks at genetic material in your blood that may occur due to a colorectal cancer tumor. A positive result from this test would lead to a colonoscopy.

Cologuard is a stool-based screening test that looks for DNA and blood in the stool that may suggest something is amiss. A positive result from this test would also lead to a colonoscopy.

Data Shows – Screening Saves Lives

Dr. Howard Koh, Assistant Secretary for Health of HHS, a champion of the 80 by 2018 campaign

Dr. Howard Koh, Assistant Secretary for Health of HHS, a champion of the 80 by 2018 campaign

We know that screening saves lives by finding and removing pre-cancerous polyps, and by detecting cancer at an early state – when it’s most curable. However, one in three Americans who should be screened for colorectal cancer are not up-to-date with their screenings even though a recent article identified colorectal and cervical cancer screenings as the most impactful cancer screenings[i].

New data released by the American Cancer Society[ii] shows that colorectal cancer incidence rates have dropped 30 percent in the U.S. in the last 10 years among adults 50 years of age and older due to the uptake of screening.

The study finds the largest decrease has occurred in people over age 65, in whom the rate of decline has surged, with the decline accelerating from 3.6 percent per year during years of 2001-2008, to 7.2 percent per year during years 2008-2010.

Because screening works, over 50 organizations have united in an effort to increase the nation’s colorectal cancer screening rate to 80 percent by the year 2018[iii].

Our comments to the FDA: 

A popular phrase in colorectal cancer screening is “The best test is the one that gets done.”

We need good screening tests, and we also need tests and strategies that address patient-reported barriers to compliance, particularly among the 23 million Americans who should be screened, but have not undergone a test yet.

We will be asking the FDA to strongly consider the sensitivity and specificity data of both tests, along with the appropriate intervals of testing. 

What are sensitivity and specificity? 

The sensitivity of a test determines its ability to correctly identify positive results. For example, the sensitivity of a colonoscopy test is the percentage of patients who were determined by colonoscopy to have pre-cancerous polyps or cancer who had a prior positive test result.

The specificity of the test determines its ability to correctly identify negative results. For example, it’s the percentage of patients who were determined by colonoscopy not to have pre-cancerous polyps or cancer who had a negative previous test result.

Why are sensitivity and specificity so important?

Sensitivity and specificity allows researchers to evaluate the accuracy and confidence in which we use screening tools. Ideally, a perfect test is never positive in a patient who doesn’t have cancer or precancerous polyps, and is never negative in a patient who does in fact have cancer or precancerous polyps.

If a novel test could improve compliance in a non-compliant population, we would like them to consider whether a limited indication might help increase compliance to screening guidelines in a very targeted way.

We have to Adapt

As technologies enter the market, we have to adapt our screening procedures and models, involving not just the physician but the entire medical team when offering colorectal cancer screening to the patient.

This takes partnering with gastroenterologists to ensure rapid diagnostic colonoscopy in appropriate patients, and developing patient-centered educational materials.

The proposed DNA/stool-based tests are an excellent example of the type of change we can make to improve quality and reduce cost. To reach our goal of 80 percent screened by 2018, we hope to continue to see improvements and access to screening for patients who are looking for non-invasive, low-cost options.

In the end, we want to ensure that new tests have the impact that we are all looking for – fewer deaths due to colorectal cancer.

Disclaimer:  Fight Colorectal Cancer believes in fully disclosing any conflicts of interest. We have worked with and received unrestricted funding from many companies who have an interest in existing and novel screening methods for colorectal cancer, including Quest Diagnostics, Exact Sciences, and Epigenomics. None of these companies, nor any of our other corporate supporters, have influenced our comments on this issue.


See screening options for colorectal cancer

Read about our research advocates program 


[i] Esserman LJ, Thompson IM, Jr, Reid B. Overdiagnosis and Overtreatment in Cancer: An Opportunity for Improvement.JAMA. 2013;310(8):797-798. doi:10.1001/jama.2013.108415.

[ii] Siegel, R., DeSantis, C. and Jemal, A. (2014), Colorectal cancer statistics, 2014. CA: A Cancer Journal for Clinicians, 64: 104–117. doi: 10.3322/caac.21220

Share on LinkedInShare on Google+Pin on PinterestTweet about this on TwitterShare on FacebookEmail this to someone

Related posts